1. Technical Field
The present invention relates to a lubricant coating for medical devices, and more particularly, to a hydrophilic polymeric coating which aids medical devices to become slippery when wetted. The lubricant coating of the present invention may be employed to reduce the coefficient of friction of catheters, arterial venous shunts, gastroenteric feed tubes, endotracheal tubes and other medical implants or polymeric substrates. The coating of the present invention also incorporates additive compounds such as anti-microbial that are released in a pharmaceutically acceptable manner. Methods are also provided for the manufacture of the subject lubricant coating and for the application of the same to surfaces of medical devices.
2. Background of the Related Art
Known lubricant coatings applied to surfaces of medical devices include coatings of polyvinylpyrrolidone, polyurethane, acrylic polyester, vinyl resin, fluorocarbons, silicone rubber, and combinations of these substances. For example, Micklus et al., U.S. Pat. Nos. 4,100,309 and 4,119,094, relate to a hydrophilic coating of polyvinylpyrrolidone-polyurethane interpolymer formed using polyisocyanate. Ratner et al., U.S. Pat. No. 3,939,049, relates to a method of grafting hydrogels for lubrication to polymeric substrates using radiation. Hungton et al., U.S. Pat. No. 3,975,350, relates to hydrophilic polyurethane polymers for use as lubricants. Storey. et al. U.S. Pat. No. 3,987,497, relates to a tendon prosthesis having a lubricant hydrogel coating. Many known lubricious coatings are prone to various disadvantages when used in the medical field. Disadvantages of such known lubricants may include insufficiently low coefficient of friction, lack of permanence such as characteristic of silicone or fluorocarbon based coatings, slipperiness when dry as well as wet thus making handling difficult, utilization of hazardous solvents in the manufacture of the same and utilization of unstable reactive materials in the manufacture of the same. Lubricants produced for medical use from unstable reactive material often require the coating solution to be prepared daily or more frequently to be useful and thereby increases waste and expense. Lubricants produced for medical use involving hazardous solvents are undesirable due to patient toxicity concerns and OSHA considerations. Also, lubricant coatings provided for inducing foreign devices into various areas of the body that are susceptible to infection and or thrombogenic reactions have failed to provide a pharmaceutically acceptable carrier for anti-microbial and anti-thrombogenic compounds.
In order to solve these and other potential disadvantages of known lubricants such as those of the above-cited patents, which are hereby, incorporated herein by reference, a lubricant coating is needed that when wetted has sufficient lubricity to be useful in the medical device field such as for medical implants and the ability to incorporate within that coating anti-microbial compounds that can be released in a pharmaceutically acceptable manner. The lubricant coating must be capable of adhering to a wide variety of substrates and resist wet abrasion. It would also be desirable to have such a lubricant coating prepared from chemically stable and biocompatible solvents. Further, it would be advantageous to prepare such coating from components that are not health hazards.